Not applicable.
Not applicable.
1. Field of Invention
This invention relates to a system of loading structured packing into a tower. Specifically, the invention describes a system comprising a removable slide mechanism for internal placement and stacking of structured packing on distribution trays inside a process tower, such as a vacuum tower.
2. Related Art and Background Information
The art of using ramps and slides for transporting material has long been known. In the field of construction and maintenance, particularly in the petrochemical industry, material slides are used primarily for removing trash and demolished materials, where the effect on the material from being slid down a chute or slide does not matter. The present invention, however, is designed specifically to minimize the damage to specialized material, specifically structured packing material.
In the petrochemical industry, process towers, including vacuum towers, are used to promote liquid/vapor interfaces between different chemicals inside the tower during chemical processing. Typically, the liquid is sprayed or sprinkled downward inside the top portion of the tower, and continues to fall to the bottom of the tower due to gravity. At the same time, the lighter vapor from the interior bottom of the tower is forced upward, typically by a vacuum pulling from the top. As the heavier liquid and lighter vapors interface by passing across each other, a chemical reaction occurs, creating the desired product.
Located within the tower is packing that provides a greater interior surface area. This large area provides more surface to which the liquids and vapors each adhere, thus promoting their interaction and subsequent chemical reaction and/or bonding. The packing is often structured packing, which is comprised of structured packing sections, each section being a quadrilateral prism comprising metal corrugated sheets. A typical dimension for a structured packing section is 72xe2x80x3xc3x9712xe2x80x3xc3x978xe2x80x3, weighing 30-40 pounds. This packing must be replaced when internal modifications or repairs to the tower are required, or when a new design of the structured packing and structured packing sections is developed. The old packing is removed by hand and discarded.
Distribution trays supporting the structured packing are located in the interior of the tower. The structured packing sections are typically stacked on top of each other until they nearly reach the next highest distribution tray in the tower. The manway to access the interior of the tower is located just below each distribution tray, and worker access to the lower distribution tray is achieved by climbing through the manway and down a portable flexible rope.
In the prior art, new structured packing was lowered through a manway with a rope down to a supporting distribution tray inside the tower. This method had two main disadvantages.
First, the process was slow. A packing replacement operation may involve over 12,000 sections of structured packing. The time required to rig each section, lower it down, and untie it from the rope was costly, both in labor cost as well as lost production time for the tower. Due to the high number of sections being singularly installed, a reduction of even one minute per section in the time required to lower it into position would have great cost savings. In the case of a 12,000 section turnaround job, a one minute per section saving would translate to reducing the time that the tower was out of operation by over eight days. It is common for such towers to produce over $1,000,000 worth of product per day. Thus, the cost savings of the current invention, which is estimated to save between 1-3 minutes per section, are significant.
Second, the process of lowering each structured packing section often damaged the packing, which is typically constructed of thin corrugated metal sheets. This resulted in reduced process efficiency due to the damaged structured packing.
It would therefore be a new and useful improvement of the prior art for a method to afford quick and efficient loading and arrangement of structured packing sections into processing towers without damaging the structured packing.
Accordingly, the objectives of this invention are to provide, inter alia, a new and improved method of loading structured packing into a process tower that:
is time efficient;
does not damage the structured packing;
can be built to accommodate standard sized structured packing;
is lightweight and easily set up within the process tower;
is relatively inexpensive; and
is easily modifiable to accommodate different heights and levels of packing.
These objectives are addressed by the structure and use of the inventive removable slide loading system. The structured packing is slid down to a receiving area, and then stacked on a distribution tray to form a packing bed. As the packing bed gets higher from the stacking of the structured packing sections, the slide is shortened and the bottom stage is raised.
Other objects of the invention will become apparent from time to time throughout the specification hereinafter disclosed.